Distributed Egg Production Functions forMeloidogyne arenaria in GrapeVarieties and Consideration of the Mechanistic Relationship between Plantand Parasite

摘要

Nematode egg production rates, as mediated by environmental conditions and host status, are important determinants of population development. Rates of egg production by Meloidogyne arenaria varied from 0.48 to 1.0 egg per female per DD₁₀ (degree days above 10 C) in different grape varieties. The length of the egg production period ranged from 550 to 855 DD₁₀ where measurable, and was generally longer in those varieties where the production rate was slow. We hypothesize that if a successful infection site is established, a constant number of eggs is produced if favorable environmental conditions prevail. Mechanistic coupling structures between plant growth and nematode population models are formulated. The nematode population influences metabolite supply through its effect on physiological efficiency and also acts as a metabolic sink; the degree of plant physiological stress influences nematode population development by affecting the sex ratio and egg production rates.